THEY are too young to walk, talk or even crawl, but tiny twins William and Ellenita Trykush can swim a length of a 25-metre pool at just nine months old.

The water babies love gliding up and down on their backs, kicking their legs to propel them along.

And as the video above shows, they even smile while they're swimming. Their achievements are even more astonishing given that they were born by emergency caesarean six weeks early.

The twins' extraordinary talent emerged during a family holiday to Cyprus in October when they began to swim under water, unaided and without armbands.

On their return to Cirencester, Gloucestershire, UK, their mother Charlotte, 35, took them to the local baby pool where they both suddenly set off on their backs.

"First they did five metres, then a width at seven metres, and then a length of 12 metres," said French-born Mrs Trykush, a former swimming coach. "There was hardly anyone in the adult pool, so I suggested to their teacher that we try the big pool. They did an entire length with me swimming underneath them on my back to make sure they were all right."

The best time to teach swimming is when kids are still very young. We all swim for 9 months inside our mothers and those instincts don't go away. We taught our kids to swim as infants too, it isn't that uncommon, and they've swam like fish ever since.